Keys won't repeat

Filter keys was introduced by the windows operating system its function is to filter out quick repeated keystrokes.
To toggle filter keys on and off hold the shift button down for eight seconds until you receive a pop up asking if you wish to turn filter keys on/off. In that pop you you will also be given the option to disable the function all together.

Press the Shift key on your keyboard at 5 times or until you see a window appear with the title StickyKeys. Click on Settings, uncheck 'Use Filterkeys' if it is checked then press OK .

1. By pressing the Shift key 5 times, an option windows will appear.
2. To remove the StickyKeys feature, click the Settings button.
3. Then in the resulting accessibility options window, click the Keyboard tab.
4. Uncheck the Use StickyKeys checkbox.
5. Click the StickyKeys Settings button.
6. Uncheck the Use Shortcut checkbox.
7. Click Apply, then click OK twice to exit all open windows.

only thing i can think of is you have turned sticky keys on, here is some info http://en.wikipedia.org/wiki/StickyKeys

It seems your sticky keys got turned on somehow. Press shift key five times and it should turn off the sticky keys feature and fix your problem.

You might be wondering what is this feature all about, so here goes:

StickyKeys is an accessibility feature to aid users who have physical disabilities, but it is also used by others as a means to reduce RSI (or a syndrome called the Emacs Pinky). It essentially serializes keystrokes instead of pressing multiple keys at a time: StickyKeys allows the user to press a modifier key, such as Shift, Ctrl, Alt, or the Windows key, and have it remain active until another key is pressed.

Ok sounds like you have "Sticky Keys" activated somehow, try this, By pressing the Shift key 5 times, an option windows will appear. To remove the StickyKeys feature, click the Settings button. Then in the resulting accessibility options window, click the Keyboard tab. Uncheck the Use StickyKeys checkbox. Click the StickyKeys Settings button. Uncheck the Use Shortcut checkbox. Click Apply, then click OK twice to exit all open windows.

Understand and use (or make sure they’re turned off) keyboard Accessibility Options. There are several types of help for those with typing difficulties, namely:
StickyKeys is an accessibility feature designed for people who have difficulty holding down two or more keys at a time. When a shortcut requires a key combination such as CTRL+P, StickyKeys will enable you to press one key at a time instead of pressing them simultaneously.
FilterKeys: You can set Windows to ignore keystrokes that occur in rapid succession, or keystrokes that are held down for several seconds unintentionally.
Bounce Keys: If you bounce your fingers on keys inadvertently, Bounce Keys will ignore repeated keystrokes until some time has passed. You choose the time period.
Repeat Keys and Slow Keys: The computer will ignore brief keystrokes according to the time limits you set. To access these Options and turn them off or on, go to your Control Panel– click Start >Settings >Control Panel >Accessibility Options.

By default it opens to the keyboard tab. If you are experiencing a sudden onset of bizarre typing behavior, your first step is to visit here and ensure that there are no checks in the three checkboxes, which indicates these Options are in use.
I mentioned that shortcuts ‘activate’ these features — such as Tab+Enter, and a couple of Alt+a letter– and so you may have turned them on unintentionally.
If you do have some difficulty with your typing, such as happens when a Mr. Arthur Itis comes to visit, or/and if you have tremors, here is where you can enable these aids and tweak their settings to get the most benefit from them. Click on the “Settings” button to see the choices. Below is the FilterKeys Settings dialogue.

In the case mentioned, my client had first held down the Shift key long enough to activate FilterKeys (because a finger “rests” there). The lady was an extremely fast typist, and this setting ignored her strokes as being too short. Since she has no use for this tool, I recommended that she uncheck the top checkbox and disable the activating shortcut.

This screenshot shows the settings for StickyKeys, and unless you have trouble holding down more than one key at the same time — such as Ctrl+Alt+Del to activate Task Manager — I suggest you uncheck the top checkbox here as well.

You can change the repeat delay times on your keyboard.
Click on the Control Panel then Keyboard icon. In the Speed tab you can change the Repeat delay and the Repeat rate settings to suit your requirements..

are you using the Alt key first on Insert? Word is a keystroke monster, and won't recognize it without that keystroke. Got Backup?

I found out what was wrong in my case. Someone had tampered with the accessibility options

So for anyone with keyboard problem check :
In Windows XP : control panel-> accessibility options -> keyboard : StickyKeys and Filterkeys checkboxes should be unchecked.

In Windows Vista : Ease of access -> Ease of access center -> keyboard : StickyKeys and Filterkeys checkboxes should be unchecked.